Police say Trooper Christopher Blais had activated his emergency lights and was sitting in his cruiser just south of exit 2 Wednesday when 44-year-old Alden Hall of Lebanon, N.H., crashed into him from behind.

Police say the police cruiser sustained significant rear-end damage and Hall's 2010 Toyota Highlander was towed with extensive damage. Police say Trooper Blais was taken to Dartmouth Hitchcock Medical Care for a precautionary evaluation but that Hall and the other passengers in his vehicle refused medical assistance.

Police believe that winter road conditions appear to be a contributing factor in the crash.